typecheck: import include/linux/typecheck.h from Linux 4.9

Copied from Linux 4.9.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

diff --git a/include/linux/typecheck.h b/include/linux/typecheck.h
new file mode 100644 (file)
index 0000000..eb5b74a
--- /dev/null
+++ b/include/linux/typecheck.h
@@ -0,0 +1,24 @@
+#ifndef TYPECHECK_H_INCLUDED
+#define TYPECHECK_H_INCLUDED
+
+/*
+ * Check at compile time that something is of a particular type.
+ * Always evaluates to 1 so you may use it easily in comparisons.
+ */
+#define typecheck(type,x) \
+({     type __dummy; \
+       typeof(x) __dummy2; \
+       (void)(&__dummy == &__dummy2); \
+       1; \
+})
+
+/*
+ * Check at compile time that 'function' is a certain type, or is a pointer
+ * to that type (needs to use typedef for the function type.)
+ */
+#define typecheck_fn(type,function) \
+({     typeof(type) __tmp = function; \
+       (void)__tmp; \
+})
+
+#endif         /* TYPECHECK_H_INCLUDED */